The purpose of the machine was obvious from the elegant cruelty of its design:

The seat restraints and the seat's solid, one-piece, gold-colored metal structure made it clear that whatever it did, was intended to be done against the initial will of those subjected to it.

There was an eldritch mass of writhing, thin silvery coils and tentacles situated at head height that somehow suggested this would be a very invasive procedure.

The transparent, yet seemingly sound-proof spherical casing placed around the seat indicated that during its active state the patient is very unlikely to be quiet.

Rynn's new friend walked around the sphere, gazing inside. She
shuddered, and looked back at Rynn.

"How ghastly," Rynn said.

"Don't your amulets do much the same thing? Make people see you
bathed in an aura of goodness and purity, interpret your words and
actions in the best possible way?"

"Haha," Rynn laughed. Alice
couldn't help noticing the laugh was warm and the voice
crystalline. Rynn's brief, wide smile was the embodiment of good-will, in a strange dissonance with the torture chamber they
were in. Apparently, the amulets worked perfectly well even when
you were aware of them.

"Perhaps they do, but in a passive way, unlike this kludgy
thing," she continued. "I mean: Tentacles that burrow into the
skull? Rather unsubtle and primitive, is it not?"

"Effective enough nonetheless, based on what we saw outside."

Rynn nodded, somberly.

How would an indoctrination (also known as brainwashing, mind control, coercive persuasion) device actually work? Can such a device even exist? For the purpose of this exercise I refer to the 'unsubtle' version:

Intensive use can turn a sworn enemy into an adoring (slavish even) friend, or (bonus level) plant a false idea or memory firmly inside one's mind as unquestionable truth.

The effects, once in place, are permanent absent other later strong(er) stimuli.

This may (or may not) damage the subject in physical and neuro-permanent ways.

It would work by known physical principles or reasonable extensions and interpolations thereof (no magic or psycho-babble), such as (but not necessarily) by acting on the pain and pleasure centers.

$\begingroup$BTW, if you go for a Pavlovian-style approach you can reset that pretty easily with a drug targeting the amygdala. Depending on what drug you're using you may be able to target other areas as well to reset non-Pavlovian behaviors and memories.$\endgroup$
– BlackJan 13 '16 at 15:25

9 Answers
9

Most of the answers so far involve some variant of torture, conditioning, or dependence. But these are crude techniques, developed by people who can only batter on the vessel which carries the mind. When you can access the mind itself, a more subtle technique may be employed...

Alice circled once more around the device.

"Have you figure out how it works?" Alice detected the slightest amount of impatience in Rynn's voice. As usual, she was doing a good job of hiding it.

"Not yet. But there's something..." She trailed off. Although she had never seen anything like it before, it was familiar to her. But there was nothing useful there, just a sense of déjà vu—or a half-forgotten memory. The image of a wolf flashed through her mind...

The human brain is an amazing organ, but is fundamentally very simple. Beyond the base instincts, there is only one function that the brain performs: the identification and recall of patterns.

Even our very memories are stored, not as a concrete sequence of images, but as a loose association of sensations. This compression is what makes our brain so powerful. If I asked you to recall this morning's breakfast, your brain uses the few salient facts it has stored to reconstruct the experience in your mind. Any detail that you wish to remember is recreated for you to inspect post facto.

But this is also the weakness of the brain. Invariably it is impossible to recall every detail of your experience. Your brain mixes together associated memories, and fabricates outright what it needs to. The brain is quite easy to fool, and while the methods it uses are often good enough, they fail surprisingly often and in predictable ways.

"Alice, talk to me!" After seeing the look on Alice's face, Rynn was no longer bothering to control her voice. She knew that Alice had realized what the device was.

Alice knew eventually someone would figure out how to duplicate the effect. But not this fast! Something like this should have taken decades to produce. "Rynn, I've seen this tech before, but not on this scale. The things they could do with this are... unimaginable. The things they've done with this..."

"Could be worse than we ever imagined." Rynn nodded her head gravely. There was only one thing to be done...

The Mære Wolf performs a type of remote side-channel attack on the brain. Through careful external manipulation of the victim's emotional state, the brain is induced to recall important memories and then associate them with the nightmare.

However, with access to a system's hardware, a low-level reformatting can be achieved. Alterations are no longer limited to memories: other, more permanent associations can be accessed and changed.

The first thing the device does as it burrows into the subject's skull is to administer an anesthetic. For its work, pain will only be a hindrance. The next chemical it releases is a memory blocker that induces anterograde amnesia, to prevent any forming memories from interfering with the procedure.

Next, the device performs a sensory probe. Although each brain stores memories in the same way, the specific workings of the memory system develop uniquely in each individual. Since everything in the brain is stored as an association, the device must learn the subject's unique sensory association map.

This is when the real work begins. The device can now make any desired change to the subject's memory and beliefs. For example, let's say that the device is used to turn Alice against Rynn. First, it will find the sensory patterns associated with Rynn, and present those to Alice's brain. It will then induce her brain to traverse all of the feelings and memories associated with that sensory pattern, breaking those associations one by one. Then it will begin to add a new set of associations. Among others, it will associate the sound of Rynn's name with hatred, and the sight of her face with revulsion. It will add memories of people telling Alice of Rynn's evil deeds, and of Rynn killing Alice's parents in front of her eyes. Finally, it will associate Rynn with enemy, and this will an absolute truth in Alice's new mind.

The key that makes this possible is the recall mechanism of the brain. The device will simulate Alice's brain to access a memory, and present the barest outline of the desired memory: "Rynn killing my parents." The brain will then fabricate details associated with that memory ("The blood-soaked knife plunging into Mother's chest again and again"), which will be fed back into the brain until a complete set of sensory information is produced. This false memory is then fed into the memory mechanisms of the brain, which store the memory alongside real ones. A similar mechanism allows the device to add and remove learned facts (including the subject's worldview and core beliefs), as well as to teach and erase skills.

Finally, as the device withdraws it heals the entry wounds it caused and induces a sleep state into the subject. This allows them to be removed from the device and placed into their new life, where they will awake in now-familiar surroundings.

"See now how the tables have turned! If you only knew how long I waited for this moment, the pain you have caused me, you would thank me for merely ending your life!" The figure bellowed as his blade plunged towards Alice, missing her by a fraction.

"Daz, what are you talking about! It's me, Alice—don't you remember?" She struggled to parry his blows. Her bewildered mind could barely register the fact that Daz could barely lift a blade the last time she saw him, but now he was definitely going to kill her.

"Remember? Remember?" Daz laughed as he struck Alice, sending her sprawling on the ground. "Do I remember the one who betrayed me? The one who made me suffer for all those years? Do I remember!" He raised his hands for the killing stroke. "Whatever trick this is, it will not save you now!"

Alice instinctively raised her arm across her face, even though she knew that this was the end. But then something happened: one of the coincidences that she had gotten used to seeing in the past two weeks. She saw, as if in slow motion, the tip of Daz's blade glancing off the device's smooth crystal enclosure. Horrified, she watched as the sword bounced back and embedded itself in Daz's skull.

She ran forward to hold the crumpled body of her childhood friend, ignoring the spray of blood that soaked her clothes. Turning away from his ruined face to look at Rynn, she spat out, "You! Why did you do that? He was... he was..." She buried her face in his shoulder and began to sob gently.

"There was nothing more that could be done for him." Rynn grabbed Alice with both hands and turned her away from the body. Looking into her eyes, Rynn said, "His mind was already gone. All that was left was his body." Rynn had to use all of her powers to calm Alice's mind. "Now you've seen what this device can do. Now you know why it has to be destroyed..."

Accesses and is able to stimulate both the pleasure and pain centers of the brain. As a bonus, include others (so making someone feel extreme cold or heat, vertigo, etc) - this allows you to tailor your treatment more closely to the target and the desired effect.

Allows you to control the target's senses - you can make them see/hear/feel/taste/smell what you want them to, basically this is VR.

Basic Conditioning:

Inject a memory of the target doing things you want (following orders, killing their friends). Combine this with stimulating pleasure.

Inject a memory of the target doing things you don't want (disobeying you, saving their king from an assassin, etc). Combine this with stimulating pain.

Go back to 1 and repeat constantly for 1-2 days.

Now bring them into a VR simulation. Put them back into those situations, but let them act however they wish. If they do what they're supposed to, you simulate pleasure. If they don't, you simulate pain. As soon as they switch, the stimulus switches (so if they start to disobey, but then do what they're told, the pain goes away and is replaced with pleasure).

They're now conditioned to associate the things you want with pleasure, and the things you don't want with pain. Do this enough and they will have an instinctive, gut reaction to act the way they want - they literally won't be able to help themselves.

For obvious reasons you can use this to create false memories as well since this puts the person effectively into VR.

Beliefs:

This is trickier, you will want to be more subtle and take more time about it. Instead of giving the target memories, you would instead ask them questions (interrogator style). Don't use pain at all here - instead, whenever they agree with you, or think along the lines you want, stimulate their pleasure centers at a very low level, enough that they just feel good but it's not obvious what you're doing. Over time this will be enough to shape their beliefs unnaturally the direction you want.

As Pavel says, brainwashing is a process. And it's a process that's been done already.

1995, Russia. The Cold War is over. Boris Yeltsin in power. There is some resentment left over from the Cold War, but generally people are starting to see Russia in a better light: they didn't, after all, nuke the lot of us, and OK there might be some good things about them.

Wait. There is some resentment left over from the Cold War. Why?

During the Cold War, there was a period known as the Red Scare. It was caused by what was, essentially, a brainwash of the US population - the US government (under President Truman) distributed so much propaganda and gave such bad impressions of the Reds (Russians) that people believed them.

This is what brainwashing is. Not cold, metal devices. Not high technology. Not even shoving a gun to someone's head or beating them almost to death. Yet it's still brutal. It's still unsubtle. Nobody ever tried to hide the fact that the US government was saying that the Reds were poison; they shouted it from the rooftops. All that mattered was that not the entire truth was told.

All you need to brainwash someone is for them to trust you a bit. People didn't totally trust the US government, but they believed that what they were doing was right - they wouldn't just lie to all their people about an issue of national interest, would they?

That belief in you enables you to tell people things. And when you tell people things enough, they start to believe them. Now you have two people spreading your cause. And when each of them makes another believe them, you have 4. Then 8. Then 16. 32. 64. 128, 256,512,1024 2048 4096 and the cycle keeps going. You now have an army of people who believe what you believe, and because you opened their eyes to this new light, they revere you above others. And nobody's going to argue with that many people, are they? Are they?

Maybe, maybe not. Maybe eventually you'll get one doubter, and they'll start a revolution.

Although Rynn's new friend - Alice - trusted her, Alice felt a sense of doubt hanging about this place. Rynn was changing people's perceptions, changing the way they looked at her and the world.

"Alice? Are you coming?"
"Give me a moment - I want to look at this thing," Alice called, indicating the machine.
"Oh come on. Don't you believe me or something?"
"Of course. Come on then."

Alice hurried off with the strange young woman. She'd forgotten her doubts for now. But deep in her mind, the sliver of doubt took root - and began to grow.

$\begingroup$@hownowbrowncow Definitely true. I used the US government's brainwashing as an example of a more successful brainwash.$\endgroup$
– ArtOfCodeApr 17 '15 at 16:22

$\begingroup$haha, very good, although the subliminal suggestion I make in the post was that Rynn already 'influenced' Alice.$\endgroup$
– Serban TanasaApr 17 '15 at 16:54

$\begingroup$@SerbanTanasa Ah, I see I've got the characters the wrong way round. Should be correct now.$\endgroup$
– ArtOfCodeApr 17 '15 at 16:55

$\begingroup$In cases like this, though, it's all about one's point of view. After all, it's certainly possible (and perhaps more realistic) to look at this the other way around. That is, the so-called "Red Scare" was actually dissemination of factual information about a real threat: the real brainwashing has been the attempts of sympathizers in academia & the media to whitewash the ugly facts. Who decides?$\endgroup$
– jamesqfApr 17 '15 at 19:50

Recently, I did read a story which had name Keep washing your clothes: During First World War, there were two opposing armies, being stuck in fortification. No one moves, no one shoots.

One weekend, there was music from opposite side. (say German). Then next happy music. Then voice: "Look. We are soldiers, you too. We are being stuck here for weeks, so lets officially cease fire and wash our clothes."

Soldiers from another side (say French) did not believe it at once, but then someone stood up and went to wash his clothes. Without being killed.

This was repeated for several weeks. Every weekend, there was happy music from German side and soldiers went to wash their clothes together.

When Germans really attacked, they faced little, to no defense, because French soldiers were already convinced that these neat people would never ever do anything bad to us

(Pun intended again)

Being from Czech Republic, some internet discussion under news articles are in mode: "What did these sleazy Americans do good to us? Do you see Putin? Strong, competent. Powerful. Russia and Czech used to be brothers. Brothers, dude." (And so on)

You dont need elaborated device. What you DO need is elaborated process

Do heroes think the villain holding them is ... well, villain? Spend some time in preparing them friendly welcome.

Show them your propaganda. Show them how bad they are. Bend reality in your favor. Let them accept it. And if they are humans, they will. Because it is pure human nature.

That plastic shell isn't to dampen the sound of screaming, it's a splatter guard. The tentacles burrow into the brain, connecting to the spinal cord, optical nerve, and other nerves, then systematically determine which nerves correspond to which sensory stimuli and muscle movements via a procedure of methodical electrical stimulation. The brain itself is removed (washed away, as it were), and a computer is put inside the skull to replace it.

Fits your bullet points:

Intensive use (all use is completely intensive) results in a friend who thinks exactly the way you programmed them to.

The effects, once in place, are permanent absent replacement by another computer or brain.

Definitely damages the subject in physical ways.

Machines that interpret signals from the nervous system already exist.

I always love working with Rynns, so I've been rather Rynn-centric in this one. It was fun choosing to push on her and see how she shifts the fates with careful words and powerful acts.

"Beautiful, isn't it," boomed a voice from behind the two adventurers. Alice whirled around to find a cleanly shaven man, immaculately dressed. In his hands he held a glass of what looked to be a fine whiskey, its color accentuating the rims of his glasses with lightly smoked lenses. Rynn appeared to have already been facing him and stood there looking at the newcomer. Alice seethed in frustration, "does that woman ever actually have to turn around, or is she always facing the right direction in the first place?"

"My name is Matthews," he continued. "I've been eagerly looking forward to meeting you both." He looked at the bodies of the guards at the doorway, "you did not disappoint."

"You built this monstrosity?" Alice exclaimed. She drew herself a hair closer to a ready stance, square to Matthews with her full body ready to strike at any moment.

"Yes, I built this monstrosity, and a beautiful monstrosity she is, is she not? It is amazing what a decade of raw will can do to father an act of creation." He took a measured sip from his glass and let the liquid slosh around in his mouth before continuing. "It is so easy to create a knife which cuts deep to the soul, but much harder to sew the wound shut again in the shape of your pleasing."

Alice took these words as though an alien uttered them, an alien whom she would never understand because she didn't want to understand. "You treat the mind like it's a toy to be played with. Even if you had found the secret of alchemy, things like this," gesticulating towards the chair, "should be destroyed. They play with too great a power."

Matthews smiled widely, and almost bowed, "It is quite an accomplishment. Of course, I cannot claim to have discovered the secret of alchemy. I simply found another way to power." He slid over to the wall nearest him and smoothly pulled a brass lever. The wall parted and rose up to reveal a room behind it. In this room, amidst gleaming brass machinery, were hundreds upon hundreds of glass vessels, stacked to the ceiling. Each was full of flesh, twisted and tumorous. The machinery seemed to breathe and pulse, forcing life into the piles of flesh. Alice could hear screaming from them. No, that's not quite right. It wasn't "hearing" that she was doing. In some odd way, she felt them screaming. Agony, it was.

Alice looked to Rynn, whose smile had faded to a thin red line. Alice's thoughts suddenly spiraled out in front of her: "I've never felt anything like this before; it's overwhelming. But what about Rynn? She picks up all sorts of details like this. It must be utterly agonizing for her to look at them. I'm amazed she's still standing."

Matthews continued on. "This is the real heart of the machine. 973 individual containers of living matter, linked by machine. You see, the secret to brainwashing is simple, really. Every mind is different, and if you simply try to force your will onto it like a battering ram, each mind comes up with a different and ingenious way to keep you out. Even if you strike at the same mind repeatedly, each time it comes up with a new solution to repel the blow. However, offer a place for the mind to grow, and it happily reveals its secrets, including the nature of its own defenses. We simply, oh, what's a good word for it.... 'inspire' these containers to be receptive to any mind and wait for the secrets to come to us."

Rynn spoke for the first time since his arrival, her voice calm, but measured. "If each mind thinks differently, as you say, it would take a very long time to teach your 'creation' how to understand our thoughts. This machine does it quickly, so I assume you're trading off size for speed. It seems difficult to store a whole mind in here. It's too small of a room. Only a fraction would fit."

"That is the true joy of my creation. I don't have to integrate with the whole mind at once. People's minds are built in layers. It's how they can stand back up again after someone knocked them down. They simply dig deeper and rise up again. They're marvelous creatures, really." Matthews had grown excited, sharing his work with others. His glass now rested on a table next to the machine's controls, and he was gesticulating to emphasize his points. "All we must do is provide sufficient... stimulation to encourage a clean break between the layers, then she integrates with the outermost layer. Once that is complete, we can simply siphon away the essence of that layer to be put back later, flush her containers again, and begin on the next layer. Once we are done, it's just a matter of using her to help put the layers back, one by one."

"And if the machine were overwhelmed by trying to chew off too big a layer?" Rynn looked skeptical, but Alice swore she heard something in her voice. There was something in her intonation that was cloyingly familiar to Alice. She'd heard it used before. She just couldn't put a finger on it. It was pushing, in a sense. Forcing. But if she hadn't been working with Rynn recently, she'd have never noticed.

"That, my dear, is where the power of statistics comes in. We measured countless minds, stripping thousands upon thousands of layers. My creation is sized sufficiently that I'm more likely to find the alchemist's stone itself than find a mind that can't be set upon by my machine. There are always edges in a person's mind to grasp, and we can find them!" He turned to stare directly at Rynn through his smoke-tinted glasses, "Why, I'd bet even you would submit to this machine in no more than 10 minutes' time."

Alice immediately raised her weapon to fully ready, crouching slightly ready to spring at Matthews' throat. He chuckled, "Relax. If I had wanted you put in the machine by force, I would have done it while I still had an army at my beck and call. Think of it more as a challenge, from one creative force to another. We are kindred spirits, trying to make sense of the world and make it suit our purposes. See what I have created. Experience it."

Rynn walked over to the window into the room crammed to the brim with containers. She touched one of them lightly. She held her finger on it for a moment, perhaps two, then pulled back quickly but controlled. Was there a purring noise from the vat as she touched it? Hallucinated sensations can be so hard to evaluate, thought Alice.

"You don't need to brainwash me. If all you care about is a strong mind to test your machine against, there are plenty of others. Why bother focusing on me at all?"

"You are right," he boomed, "but you are here, so it seems like you would be the best candidate for the job. What do you say? I know you are special. Are you up for testing what you are made of?" Rynn did not respond.

Matthews paused for a bit, picked up his whiskey glass and turned to Alice, "Tell ya what: how about I sweeten the deal. I know Rynn wouldn't be interested in a trade for information, but you just might be. It's amazing the things you learn when shucking minds is your occupation. You'd be amazed at how much your parents wished they could have told you, but never got the chance. Think of what I might be able to tell you, if only she gave my creation a try." He raised his glass in her direction.

Alice was electrified. Until now, the focus had been on Rynn and Rynn alone. Rynn remained cool, calm, and...well... Rynn. Now the attention was on her. Matthews's stare was infectious. She almost felt the excitement of discovery flowing from his eyes through the smoked lenses. Instinctively she began calming exercises, but every adventurer knows the one place those exercises don't work is the place you need them to work.

Rynn rescued her, "So you want a strong mind to test the mettle of your machine, and you're willing to offer Alice information you think she might be interested in, regardless of the result of the test?" Matthews smiled and nodded.

Rynn said nothing more to him. She walked up to the machine and sat down. Matthews deftly hooked up several electrodes and hypodermic needles, then shimmied to the control panel like an excited child running off to his tree fort.

Alice looked at Rynn, then at Matthews, then back at Rynn. She swore she saw just a flash of a smile. Thinking back, she almost even remembered feeling the vats stop screaming and smile too. It wasn't for long: just a split second before Matthews flipped a switch and sent the vats into indescribable wracking pain.

Rynn stepped down from the machine. It wasn't quite a stagger, but it was certainly not Rynn's usual level of grace in movement. She took a few steps towards Alice, and rested a hand on her shoulder. Rynn's breath was calm, but it felt like that was the only calm part left in her. The rest of her moved like strands of a wire flexed one too many times.

"What now?" asked Alice. She looked over at Matthews standing rigid next to the control panel, knife against his own throat. He quivered slightly, but other than that, he dared not move. "What are you going to do with him?"

"I'm not going to do anything. He's not mine to deal with. He's yours." Alice frowned in confusion at Rynn's words. Rynn continued, "If I had tried to control his mind while in that machine, he'd have felt it and stopped it. He's no fool, and his attention was completely devoted towards me. I had no opportunity. You, however, you did have the opportunity. He wasn't paying as much attention to you as he was to me."

"But, I didn't do anything. He wasn't even hooked up to the machine!"

"Wires and chemical injections never had much to do with it. Regardless, he is not mine to deal with."

Alice thought for a moment, "If I did this, and not you... I don't even know what I 'did!' What would have happened if I didn't?"

"I had confidence." Rynn raised up and walked out the door. The vats of matter were broken and leaking. The machine would be inert soon enough. Alice swore she saw wisps of something slowly uncoiling from the containers and dancing about in their own right. Their dance was free spirited, but seemed to drift in the direction Rynn was walking. Rynn even seemed to walk a little straighter as the wisps got near, offering them direction. They walked with her.

None of this made any sense to Alice. Just a few weeks earlier, she could trust her senses. She lamented the continued streak of hallucinations that seemed to follow her when she was around Rynn.

Alice looked back at Matthews. His eyes cried for death, but his hand seemed to refuse the order. His lips trembled, as though they were begging for Alice to give a command but could not form the words on his lips. It truly looked like he would stand there in pain until he starved to death if she gave the order. "Oh bother," she thought, "what to do, what to do."

$\begingroup$I had fun =) I've been playing a lot with models of what things like branwashing could mean. I thought about just writing them down, but I figured there's a lot more room for creativity if I don't try to write it as a dry list of rules. The interaction bit is the key, though. I think it is almost impossible to brainwash someone with a one way street and leave them functioning afterwards. Your machine has to litsten to what they have to say too.$\endgroup$
– Cort AmmonApr 18 '15 at 17:22

You might want to look into Subliminal advertising. That is putting 'hidden messages' in images and so on by putting one frame between the others. this frame is repeated but you don't see it, your sub conciousness picks it up though. Or so is the theory, I think the myth was busted a time ago.

Nonetheless you could use it, forcing a human into an endless repeating series of certain images, 1 image can speak a thousand words and all that, and they would become slaves eventually.

It's not a genuine loyalty; it's craving for a drug and dreading the hunger.

The machine merely implants remotely controlled capsules in the brain of the victim, and delivers enough of the drug to build up a very serious addiction.

As long as you stay obedient, enough drug is delivered to keep the addict satisfied. Positive actions are rewarded with larger doses. Negative actions deliver a counter-drug, causing not only craving but incredible torture.

Some training, some controlled opportunities to resist that trigger the punishment, some opportunities to obey that bring bliss beyond imagination, and soon the victim learns to be a good puppet.

$\begingroup$Interesting, but couldn't you skip the chemical intermediaries and go straight for the pleasure and pain centers? Added bonus: no habituation.$\endgroup$
– Serban TanasaApr 17 '15 at 12:15

$\begingroup$@SerbanTanasa: Possibly; still, for it to be permanent you'd need an implant, otherwise the conditioning will wear off.$\endgroup$
– SF.Apr 17 '15 at 12:37

$\begingroup$that's already how television and pr0n work by stimulating dopamine response.$\endgroup$
– hownowbrowncowApr 17 '15 at 16:19

$\begingroup$@hownowbrowncow: Yes, but these are hardly unbreakable addictions, especially if a strong motivation to the contrary appears.$\endgroup$
– SF.Apr 17 '15 at 16:22

1

$\begingroup$By the way, want to make it really abhorrent? Make the "implant" a live parasite. Inject some worms into that brain...$\endgroup$
– SF.Apr 17 '15 at 16:27

Pain doesn't work. 'Interviewees' will tell you whatever you want to hear, especially lies, if they believe it will make the pain stop. Fear however is a different matter.

Triggering the body's Fight or Flight response when the interviewee is heavily restrained would induce a state of absolute terror, which if focused on a person or object, could be used to coerce information.

It's far more difficult to lie convincingly when terrified and by ramping up the FoF response by directly triggering the release of the required neurotransmitters using the tentacles, the only limit would be when the interviewee has a heart attack from fear - which is highly survivable provided trained medical staff are on hand.

In terms of damage, the interviewee will probably be left with a permanent phobia of whatever was used. Interesting examples: The dark - reduce the lights when the Interviewee isn't co-operating. A Mirror - not sure if the Interviewee would develop a 'bloody mary'-type fear or just a fear of their own reflection. Flowers - can you imagine the psychological trauma that a snow drop could produce? Now imagine a sunflower. For the finale - a bouquet.